Lockable door latch



Sept. 21, M. J. SNYMAN LOCKABLE DOOR LATCH Filed Nov. 4, 1963 s Sheets-Sheet a F/G7. j

/1 50 4 7 45 i I 'I /o W r 7 8 /7a 46 4 United States Patent Office 3,206,954 Patented Sept. 21, 1965 3,206,954 LOCKABLE DOOR LATCH Mattheus Johannes Snyman, Odendaalsrus, Orange Free State, Republic of South Africa, assignor to Pres-Pol Lock Company Limited, Johannesburg, Transvaal, Republic of South Africa Filed Nov. 4, 1963, Ser. No. 321,163

Claims priority, application Republic of South Africa,

Nov. 14, 1962, 62/4792 10 Claims. (Cl. 70-150) This invention relates to improved door latches and door locks of the thrust-operated kind requiring a thrust or pull upon the knob spindle or shaft for retraction of the bolt to permit the opening of the door in the direction of the force applied to such spindle or shaft.

According to the invention, a door latch includes, a casing adapted for mounting in a door, a latch bolt slidably movable in its longitudinal direction and swingable in a transverse direction within said casing and consisting of a catch rigidly associated with and projecting from one end of a mounting member, resilient means biassing the latch bolt in one longitudinal direction with the catch extending through one end of the casing, stop means on the latch bolt limiting the extent of extension of the catch, a manually operated bar axially slidably located transversely through the casing and door and having knob-like members on the ends, stop means limiting the sliding movement of the bar to two alternative positions, resilient means for biassing the bar to one of the alternative positions, a passage across a portion of the bar disposed within the casing, a formation on the mounting member slidingly engagcable along said passage when in alignment therewith for longitudinal catch retracting movement of the latch bolt, a striker adapted for fixing on a door frame member forming a keeper and further adapted for swinging the latch bolt in transverse directions and for effecting catch retraction by a wedging action on opening and closing of the door, and shoulder means on the mounting member engageable across the bar when the mounting member is not in alignment with the passage for blocking the longitudinal movement of the latch bolt, such alignment being attained, on opening the door, by displacing the bar to an alternative position against the action of the bar biassing means while the latch bolt is swung in one direction by transversely directed pressure between the catch and one side of the striker, whereas on closing the door the mounting member is aligned with the passage, when the latter is in the position maintained by the biassing means of the bar, by swinging of the latch bolt in the opposite direction when striking the other side of the striker.

The catch is preferably of substantially part elliptical shape when viewed at right angles to the direction of the swing of the door and provides substantially convergingly arranged curved side faces adapted for engaging the striker. The catch mounting member is of a lesser thickness than the maximum thickness of the catch between the curved faces and extends from the thick end of the catch substantially parallel to the centre line of the catch.

The latch bolt is biased to that position in which the catch is extended outwardly from one end of the casing and the swinging edge face of the door by a spring. The latch bolt is arranged for swinging in a transverse direction when either of the converging, and preferably curved side faces of the catch is thrust on to a side-face of the striker. The biasing means of the knob or handle mounting bar is by means of a spring adapted to place and normally retain the said bar in that position in which the passage is located in a position to receive the coacting formation of the latch bolt when the latter is swung transversely on closing of the door, due to thrusting the catch on an outwardly directed face of the striker.

With the door latch key operated locking means may also be provided whereby the longitudinal movement of the latch bolt may be blocked or otherwise prevented.

The passage associated with the slidable bar may be in the form of a transverse groove or hole whereas the coactin g formation on the end portion of the catch mounting member of the latch bolt may be in the form of a deep notch presenting parallel sides and slidable embracingly over the reduced portion of the bar at the groove or a protrusion capable of sliding through the hole in the bar.

The handle or knob mounting bar is preferably of non-circular cross-sectional shape and passes through inline complementarily shaped holes provided in two opposite sides of the lock casing and preferably also through similar holes provided in escutcheon plates fixing on opposite faces of the door. The biasing spring means for the bar is conveniently provided in a space between an escutcheon plate and the latch casing while the biasing spring means of the latch bolt is located internally of the casing. The stop means, limiting the longitudinal movement of the latch bolt in the direction of extension of the catch, is conveniently formed by shoulder means engaging a part of the lock casing whereas the stop means for the opposite direction also consist of a shoulder which engages the said handle or knob mounted bar.

The latch means according to the invention is readily adaptable for leftor right-handed swinging doors.

The striker preferably provides rounded or oblique and convergent faces at the positions of engagement by the catch of the latch bolt.

The invention will now be described with reference to the accompanying drawings and from which further features will be apparent. Like reference numerals refer to like parts throughout the several views.

In the drawings:

FIGURE 1 is a side view of a door latch and door lock according to the invention and of which the cover plate on one side has been removed;

FIG. 2 is a vertical cross-section of the lock on line IIII of FIGURE 1 and shown fitted in a door;

FIGURE 3 is a cross-section on line III-III of FIG- URE 2, showing in addition the door frame receiving the swinging edge of the door;

FIGURE 4 is a view similar to FIGURE 1 showing a modified form of construction of a door latch and lock according to the invention;

FIGURE 5 is a vertical cross-section on line V-V of FIGURE 4, showing the latch and lock fitted in a door;

FIGURE 6 is a horizontal cross-section on line VI-VI of FIGURE 5, showing also the door frame receiving the swinging edge of the door;

FIGURE 7 is a fragmentary side view of a door lock according to the invention and showing a further modified form; and

FIGURE 8 is a cross-section on line VIII-VIII of FIGURE 7.

The door locks shown in the drawings are of the mortice lock kind for engagement and fixing in a mortice 1 provided in the swinging edge face of a door 2. The latch and lock is provided with a flat rectangular casing 3 having on one end a fixing plate 4 in which a non circular port is provided which communicates with the interior of the casing 3. One large side face of the casing 3 is a removable cover 5 held in position by screws (not shown), engaging tapped holes 6 provided in the nonremovable side 7 of the casing 3.

The latch bolt consists of a catch 8 which is rigidly fixed to a mounting member 9. The mounting member 9 is movably located interiorly of the casing 3 whereas the catch 8 extends outwardly of the casing through the port provided in the fixing plate 4. The catch, in plan view, is of substantially convergent shape but preferably provides curved side faces connected by a small radiused end or nosed face 11 and is thus of substantially partelliptical shape. The wide end 12 is symmetrically fixed to an edge of a plate forming the mounting member 9. The plate is substantially thinner than the catch. The latch bolt formed by the catch 8 and the mounting member 9 is slidably movable in the direction of the plane of the mounting member but is normally biassed for the catch 8 to be retained in the maximum extended position from the lock casing 3.

Transversely through the lock casing 3, a knob-bar 13 is axially slidably and non-rotatably mounted. The bar 13, which is of non-circular shape and preferably of square cross-sectional shape, slidably passes through complementarily shaped holes in the removable and fixed casing sides and 7 and also in escutcheon plates 14. On the ends of the bar 13, knobs 15 are fixed, preferably in adjustable fashion. ,The bar 13 is biassed in one of two alternative positions by means of a compression spring 16 placed around the bar 13 and engaging with one end against the inside of an escutcheon plate 14 and with the other end on a part fixed to the bar 13.

In the form of construction as shown in FIGURES 1, 2 and 3, the biassing means for the catch 8 and its mounting, member 9 consists of a compression spring 17 located in a cavity 18 formed within the plate forming the mounting member 9. One end of the spring 17 engages over a short lug 19 presented within the cavity 18 whereas the opposite end engages a transversely disposed rigid lug 20 attached to or formed from the fixed side 7 of casing 3 and which lug 20 extends into the caivty 18. Said lug 20 in addition forms a stop to limit the extent of movement of the catch 8 and mounting member 9 towards the left and consequently the extent of projection of catch 8 beyond the outer face of plate 4. The end of the mounting member 9, opposite to the end providing the catch 8, is shaped to form a deep longitudinally arranged notch 21 and a tongue-like extension 22.

In that portion of the bar 13, at all times located within the casing 3, a transverse groove 23 is provided through which the marginal portion 24 of the mounting member 9, on one side of the notch 21, is extendable when such transverse groove 23 is in register with the mounting member 9. When not in register, the face 25 of the mounting member 9 engages against the face 26, of bar 13 to block the retracting movement of the mounting member 9 and the catch 8. On the removable and non-removable sides 5 and 7 of the casing 3, face regions 27 are presented which are slidingly engaged by the curved and convergingly arranged side faces 10 of the catch 8 and on which such catch 8 is capable of forming a rolling or swinging action. The mounting member 9 has a thickness substantially less than the internal width of the lock casing 3 thus allowing for the said member 9 to perform a swinging action in a transverse direction within the catch 8.

In one side 5 or 7 of the casing 3 an inwardly projecting stop 28 is provided which limits the swinging action of the member 9 to a substantially central position within the casing 3 when swung to one alternative position. In the other alternative position of the latch bolt the swinging action is arrested on engagement with the other casing side. The stop member 28, shown in FIGURE 3, is in the form of a small screw engaging in a threaded hole provided in a recessed portion 29 of the casing side. Preferably such recess 29, providing a screw-threaded hole, is provided in both the removable and non-removable sides 5 and 7 of the lock casing 3 and in either of which the screw 28 may be screwed, depending on the direction of swinging movement required trom the mounting member 9 from its central position within the 4 casing in order to adapt the latch for a door required to swing to the left or to the right.

On the bar 13 a stop forming projection 30 is provided which is engaged by the spring 16 and adapted to engage a side of lock casing 3 whereby the extent of axial movement of the bar 13, in one direction, is limited. Movement in the opposite direction, against the action of spring 16, is arrested by the spring 16 when fully compressed against the inner face of an escutcheon plate '14. The stop 30 may comprise a pin engaging transversely into or through the bar 13 and from which it projects outwardly.

The bar extends through holes 31 provided transversely through the door 2 and intersecting the mortice 1. Said holes 31 are of sizes to provide suflicient space around the bar 13 for the spring 16 and stop 30.

In the door frame 32, providing a rebate 33 for receiving the swinging edge part of the door 2, a catch receiving keep formation or recess 33 is provided and with which a striker plate 34 is associated. 'Ihe striker plate 34, which is tfixed to the door frame member 32,

provides a pair of oblique faces 35 and 36 for engagement by the side faces 10 of the catch 8 in order to apply forced retraction of the catch 8 against the action of spring 17 by a wedging action produced between the catch 8 and said faces 35 and 36.

In the normal state of the lock the transverse groove 23 of the bar 13 is disposed adjacent one side of the lock casing. For opening of the door an axially directed movement is applied to the bar 13 to the maxim-um permissible extent whereby the transverse groove 23 is transferred to a substantially central position within the lock casing. Continuance of the application of the axially directed force on the bar '13 causes the catch 8 to be forced against the inner oblique face 36 of the striker plate 34, whereby a wedging action is applied to the catch 8'ca1using longitudinal displacement of the member 9 and by virtue of such member being in alignment with the centrally disposed position of the transverse groove 23, permits the member 9 to be forced along the casing and groove 23 [for retraction of the catch '8. On release of a bar 13, the bar is transferred to its normal position, as is shown in FIGURES 2 and 3.

When closing the door 2, and on the catch 8 striking the outside oblique face 3 5 of the striker plate 34, the member 9 is swung in the direction of swing of the door and toward and on to casing side 5 for alignment with the transverse groove '23 of bar 13. On continued pressing of the catch '8 against the outside face 35 of striker plate 34, the catch 8 is forced inwardly by a wedging action which is possible due to the member 9 in the said position being in alignment with the transverse groove 23 lgzrmitting inward displacement of the-catch 8 and mem- Forlocking of the catch in the extended position, key operated means is provided in a rear region of the casing 3 and which conveniently consists of key operated tumbiers and a key displaceable element 40. In the operative position of element 40, it is disposed between the rear end of the tongue 22 and the casing for blocking the retracting movement of the member 9 and catch 8. The key operated lock means 37 may be of any known kind.

In the form of construction of the invention shown in FIGURES 4, 5 and 6, the transverse passage or groove 23 is provided in the underside of the bar 13 instead of in the top, as is shown in the form of the invention shown in FIGURES l, 2 and 3, while a shoulder 25 is provided for engaging the bar 13 when the transverse groove 23 of the bar 13 is out of alignment with the member 9. The mounting member 9 is provided on its .front end with shoulder forming regions 39 for abutting against the internal surface of the plate 4.

A further modification resides in the provision of a leaf-like spring 17a for resiliently biasing the catch 8 to the extendedposition. Said spring 17a may. comprise a wire-like element anchored by one end to the casing and having the opposite end passing through a cavity formed by an outwardly directed loop-like embossment 41 provided in the mounting member 9a. With this arrangement the leaf spring 17a may be arranged to return and retain the mounting member 9a to and in a substantially central position in the casing 3 and out of alignment with the transverse groove rovided in the bar 13 when the :bar 13 is in either of the alternative positions. In this form of construction, the stop 28 is not employed. The limiting of the alternative transversely swung positions is effected by casing sides 5 and 7, which may be provided with embossments for such purpose.

The FIGURES 4, 5 and 6 also show a modification in respect of the knobs 15, which each provides a flanged sleeve extension 42 slidably engageable over and adjustably fixable to the bar 13, while in respect of one of the knobs 15, the Spring 16 engages flange 43 of such sleeve 42 and the inside of one escutcheon plate 14. With this arrangement the portions of the bar 13, otherwise exposed, are now encased by the sleeves 42, thus enhancing the appearance of the latch and lock.

The stop 30 may be in the form of a pin or cotter extending through the bar and providing protrusions beyond two opposite faces of the bar 13. The fixed end of the Wire-like leaf spring 17a is preferably inserted or threaded through a diametrical hole of a pin 44, fixed to the fixed side 7 of the casing 3.

In the form of the invention, shown in FIGURES 7 and 8, the modified features reside in the provision of a transverse hole 47 in the bar 13 instead of the transverse groove 23, while the mounting part 9b is provided with a pin-like end extension 45 capable of extension through said hole 47 when in alignment therewith. The end of the pin-like extension 45 normally engages in a longitudinal groove 46 provided in a face of the bar 13 and from which groove the hole 47 extends. The coacting engagement of the extension 45 in the groove 46 provides guiding and locating means for the catch mounting member 912.

The catch mounting member b in this form of construction may consist of a bar providing a transverse hole 48 through which a wire-like leaf spring 17a or the like passes. The spring 17a is also fixed by means of a pin 44 providing a diametrical hole in which the fixing end of the leaf spring 17a is engaged. The stop means in this form of construction, for limiting the extent of projection of the catch 8 may consist of a pin 50 passing through the thick end portion of the catch 8 and projecting beyond the opposite fiat faces to a limited extent for engaging the plate 4 of the lock casing 3.

The form of the door latch and lock according to FIG- URES 7 and 8 may be employed when constructing a latch or lock employing a cylindrical casing for engaging a hole bored transversely into the swinging edge face of a door whereas the hole in the door, through which the bar extends, is also a circular hole intersecting the casing receiving hole at right angles.

The striker plate 34, shown in FIGURE 6, is of substantially similar construction as that as shown in FIG- URE 3, but provides a flat region 48 between the oblique faces 35 and 36.

The operation of the modified forms of the invention is similar to that as described with reference to FIGURES 1, 2 and 3. All the forms of the latch or lock are readily converted for leftor right-hand opening doors. In all cases the direction of operation of the bar 13 is in the same direction as that in which the door is to be swung.

In the aforegoing description reference has been made to a mortice lock only. The invention is nevertheless also capable of being constructed to serve as a rim lock without departing from the features of the invention.

I claim:

1. A door latch including, a casing adapted to be mounted in a door, a striker plate adapted for fixing on 6 a door frame member for the door, a rigid latch bolt slidably movable in its longitudinal direction and swingable between stops in a transverse direction Within the casing and comprising a catch and a catch mounting member, said catch being adapted for retractable extension from one end of the casing for engagement of the striker plate and is of a generally wedge shape presenting convex faces on the convergent sides and of which portions are rollingly and slidably engageable on a pair of spaced internal face regions presented on opposite sides of the casing, a compression spring engaging the casing and the mounting member biassing the latch bolt in one longitudinal direction for the catch to extend through one end of the casing, stop means on the mounting member limiting the extent of projection of the small end of the catch, a manually operated bar guided for slidable movement in its axial direction transversely through the casing and the door and mounting knob-like members on the ends, stop means limiting the movement of the bar to two alternative positions, a spring biassing the bar to one of the alternative positions, a groove transversely across a portion of the bar disposed within the casing in any position of the bar, a deep notch on the end of the mounting member opposite to the end from which the catch projects and slidably engageable along the groove on alignment therewith for longitudinal catch retracting movement of the latch bolt, oblique faces on the striker plate for engagement by the convex faces of the catch and adapted for swinging the latch bolt in the transverse directions and for applying a wedging action to the catch for retraction thereof when thrust onto the striker plate on opening and closing the door, and shoulder means on the mounting member engageable across the bar when the mounting member is not in alignment with the groove for blocking the longitudinal movement of the latch bolt, said alignment being attained on opening the door, by displacing the bar in the direction of the intended swinging of the door while on closing the door the swinging action applied to the latch bolt places the deep notch in alignment with the groove in the bar when the latter is in the position to which it is restored by the biassing means of the bar.

2. A door latch including, a casing adapted to be mounted in a door, a catch keeper forming striker plate adapted for fixing on a door frame member for the door, a latch bolt slidably movable in its longitudinal direction and swingable in a transverse direction between stops within said casing and comprising a rigid unit consisting of a catch of substantially wedge shape and a coaxial mounting member for the catch projecting from the wider end of the catch, said mounting member having a deep notch therein, convex curved faces on the converging sides of the catch adapted for sliding and rolling-like engagement on a pair of parallel spaced face regions presented on the insides of two opposed sides of the casing, a spring fixed by one end to the casing and engaging a hole in the mounting member -by a portion on the opposite end region for biasing the latch bolt in one longitudinal direction for extension of the smaller end portion of the catch through one end of the casing and for resiliently retaining the mounting member in a position substantially coaxially within the casing, a manually operated bar axially slidably located transversely through the casing and door and having knob-like members on the ends, a biassing spring on the bar urging the bar to one of two alternative positions, a groove transversely across a portion of the bar disposed within the casing in any position of the bar, said deep notch in said mounting member slidingly engageable along said groove on alignment of the mounting member with the groove for longitudinal catch retracting movement of the latch bolt, a pair of convergingly arranged oblique faces on the catch keeper forming striker plate adapted for swinging the latch bolt in transverse directions when the catch is thrust against either of said faces and for subjecting the catch to a wedging action for retraction into the casing on opening and closing of the door, and shoulder'means on the mounting member engageable across the bar when the mounting member is not in alignment with the passage for blocking the longitudinal movement of the latch bolt, said alignment being attained on opening the door, by displacing the bar from one alternative position to the other alternative position against the action of the bar biassing spring while the latch bolt is swung in one direction by transversely directed pressure between the catch and one oblique side of the striker plate, whereas on closing the door the mounting member is aligned with the groove when the latter is in the alternative position resiliently maintained by the biassing means of the bar, by swinging the latch bolt in the opposite direction when striking the other oblique side of the striker plate.

3. A door latch including, a casing adapted to be mounted in a door, a keeper forming striker plate adapted for fixing in a door frame member in which the swinging edge of the door is received, a latch bolt slidably movable in its longitudinal direction and swingable in a transverse direction between stops within said casing and consisting of a catch rigidly associated with and projecting from one end of a mounting member, a pair of convex faces arranged convergingly on opposite sides of the catch of which the widest region is slidably and rollingly engageable on a pair of inwardly directed and parallel spaced face regions presented by opposite sides of the casing, spring means biassing the latch bolt in one direction with the catch extending through one end of the casing, stop means on the latch bolt limiting the extent of projection of the catch from the casing, a manually operated bar axially slidably and non-rotatably located transversely through the casing and the door and having knob-like members on the ends, escutcheon plates for fixing onto the door faces and presenting means for slidable and non rotatable location of the bar, stop means limiting the sliding movement of the bar to two alternative positions, spring means engaging an escutcheon plate and a projection on the bar for biassing the bar and associated parts to one of two alternative positions of the bar, a passage across a portion of the bar disposed within the casing in any position of the bar, a formation on the mounting member slidably engageable along the passage when in alignment therewith for longitudinal catch retracting movement of the latch bolt, a pair of convergingly arranged faces on opposite sides of the striker plate adapted for swinging the latch bolt in transverse directions when the catch is thrust onto the striker plate and for effecting catch retraction by a wedging action on opening and closing of the door, and shoulder means on the mounting member engageable across the bar when the mounting member is not in alignment with the passage for blocking the longitudinal movement of the latch bolt, said alignment being attained, on opening of the door, by displacing the bar to an alternative position against the action of its biassing spring means while the latch bolt is swung in one direction by transversely directed pressure between the catch and one oblique face of the striker plate, whereas on closing the door the mounting member is aligned with the passage when the latter is in the position resiliently maintained by the biassing spring means of the 'bar, by swinging of the latch bolt in the opposite direction when striking the other side of the striker plate.

4. A door latch including, a casing adapted to be mounted in a door, a keeper adapted for fixing in a door frame in which the swinging edge of the door is received and comprising a striker plate presenting a pair of convergingly arranged oblique faces, a latch'bolt slidably movable in its longitudinal direction and swingable in a transverse direction between stops within said casing and consisting of a wedge shaped catch rigid on and projecting from one end of a mounting member, convex curved side faces on the catch arranged convergingly and presenting rounded faces which when thrust against the oblique faces of the striker plate causes transverse swinging and retraction of the latch bolt by a wedging action while said rounded faces slidably and rollingly engage a pair of parallel spaced internal face regions presented by two opposite sides of the casing, spring means resiliently biassing the latch bolt in one longitudinal direction with the catch extending through one end of the casing, stop means on the latch bolt limiting the extent of projection of the catch from the casing, a manually operated 'bar slidable in its axial direction transversely through the casing and the door and having knob-like members on the ends, escutcheon plates for fixing to the door faces and providing guide means for the bar, stop means limiting the sliding movement of the bar to two alternative positions, spring means for resiliently biassing the bar to one of the alternative positions, a transverse hole through a portion of the bar which is within the casing in any, position of the bar, a pin-like projection on the mounting member opposite to the end mounting the catch and which extension is slidably engageable through the transverse hole of the bar when in alignment therewith for longitudinal catch retracting movement of the latch bolt, shoulder means on the mounting member engageable across the bar when the pin-like projection of the mounting member is not in alignment with the transverse hole of the bar for blocking of the longitudinal movement of the lat-ch bolt, said alignment being attained on opening the door by displacing the bar to one of the alternative positions against the action of the bar biassing spring means while the latch-bolt is swung in one direction by transversely directed pressure between the catch and one oblique face of the striker plate whereas on closing the door, the pin-like projection of the mounting member is aligned with the hole when the latter is in the position maintained by the biassing means for the bar, by swinging of the latch bolt in the opposite direction when striking the other oblique side of the striker plate 5. A door latch as claimed in claim 4, wherein the bar is provided with a longitudinal groove in a longitudinal face directed towards the catch and with which the transverse hole in the bar communicates, said groove providing guiding and locating means for the free end of the pin-like extension of the mounting member.

6. A latch for a door comprising a casing, a latch bolt sliding in axial and tilting in transverse directions in said casing and consisting of a squat catch element rigidly attached to a mounting member therefor, a spring held by one end on a part of the casing and engaging by the other end said latch bolt urging the catch element to extend from one side of the casing, a striker plate fixed to a frame for the door and having convergent faces for re tracting displacement of the latch bolt by a wedging action on pressing either side of the catch element against either of the convergent faces, said catch element having a pair of substantially outwardly converging face forming sides which present convex shaped side cheeks slidingly and rollingly engaging at the thickest portion of the catch element spaced internal face portions of two opposite sides of the casing, said mounting member being of smaller thickness than the widest part of the catch element and the internal spacing of the casing sides and extending substantially coaxially from that end of the catch element opposite to the convergent end of the catch element which is outwardly extendable from the casing for the latch bolt to tilt in transverse directions by rolling actions of the catch element on the internal face portions of the casing sides to an extent limited by contact of the mounting member with other internal face regions of the casing sides, a formation on the mounting member adjacent the end opposite to the end having the catch element and which formation is engageable in a transverse complementary formation in a bar which is slidable trans versely through the casing and the door and having handle means on the ends, a spring on said bar resiliently biassing the bar in the direction of its axis to one of the two limiting positions and in which position said formation of the bar is disposed adjacent the internal face of one of said casing sides and which formation is transferred towards the opposite side of the casing on axial displacement of the bar against the action of the bar biasing spring; the arrangement being such that retraction of the bolt is permissible on alignment of the complementary formations of the mounting member and bar, said alignment being attained on opening the door after displacing the bar against the action of the biasing spring while the latch bolt rolls in one direction by transverse pressure between the catch element and one face of the striker, whereas on closing the door the complementary formations are again aligned when the bar is in the position maintained by its biasing spring while the latch bolt is swung in the opposite direction on being pressed onto the other face of the striker.

7. A latch for a door according to claim 6 in which the catch element of the lat-ch bolt, when viewed in the direction perpendicular to the directions of swing and retraction thereof, is of a shape consisting of the larger portion or an elipse of which one narrow end portion is cut off, and having on a wide fiat edge face the mounting member extending substantially coaxially from the catch element.

8. A latch for a door according to claim 6 in which a stop element is provided, which protrudes transversely into the casing from one side of the casing and adapted to limit transverse swinging of the latch bolt in one direction to a substantially central position within the casing, said stop element being mountable at corresponding positions on either side of the two opposite sides of the casing.

9. A latch for a door according to claim 6, in which the catch element mounting member of the latch bolt consists of a rigid plate having a parallel sided deep notch extending longitudinally from the end opposite to the end carrying the catch element and in a direction towards said catch element, said notch presenting a formation engageable along a complementary transverse groove formation provided in the transverse and slidable bar, the width of said notch being substantially equal to a reduced thickness portion of the bar at the transverse groove for sliding over said reduced portion of the bar on alignment of the plate with the transverse groove, whereas a transverse plate edge portion, adjacent said notch, forms an abutment for engaging onto a side face of said bar when the said notch and groove are out of alignment.

10. A latch for a door according to claim 6 in which the biasing means of the latch bolt consists of a compression spring disposed within a longitudinally arranged rectangular cavity in the mounting member of the latch bolt, said spring being mounted by one end on a transverse projection extending inwardly from one side of the casing and by the other end on a transverse edge face of said cavity, said transverse projection forming guide means for the latch bolt and stop means limiting the extent or outward projection of the catch element from the casing on engagement by an opposite transverse edge face of said cavity.

References Cited by the Examiner UNITED STATES PATENTS 1,486,552 3/24 Swanson 9474 1,554,839 9/25 Brown 70150 1,772,791 8/30 Weaver 70150 2,082,195 6/37 Williams 29274 2,162,031 6/ 39 Reavill 29274 3,057,649 10/62 Check 292-74 FOREIGN PATENTS 121,977 6/ 48 Sweden.

ALBERT H. KAMPE, Primary Examiner.

BOBBY R. GAY, Examiner. 

3. A DOOR LATCH INCLUDING, A CASING ADAPTED TO BE MOUNTED IN A DOOR, A KEEPER FORMING STRIKER PLATE ADAPTED FOR FIXING IN A DOOR FRAME MEMBER IN WHICH THE SWINGING EDGE OF THE DOOR IS RECEIVED, A LATCH BOLT SLIDABLY MOVABLE IN ITS LONGITUDINAL DIRECTION AND SWINGABLE IN A TRANSVERSE DIRECTION BETWEEN STOPS WITHIN SAID CASING AND CONSISTING OF A CATCH RIGIDLY ASSOCIATED WITH AND PROJECTING FROM ONE END OF A MOUNTING MEMBER, A PAIR OF CONVEX FACES ARRANGED CONVERGINGLY ON OPPOSITE SIDES OF THE CATCH OF WHICH THE WIDEST REGION IS SLIDABLY AND ROLLINGLY ENGAGEABLE ON A PAIR OF INWARDLY DIRECTED AND PARALLEL SPACED FACE REGIONS PRESENTED BY OPPOSITE SIDES OF THE CASING, SPRING MEANS BIASSING THE LATCH BOLT IN ONE DIRECTION WITH THE CATCH EXTENDING THROUGH ONE END OF THE CASING STOP MEANS ON THE LATCH BOLT LIMITING THE EXTENT OF PROJECTION OF THE CATCH FROM THE CASING, A MANUALLY OPERATED BAR AXIALLY SLIDABLY AND NON-ROTATABLY LOCATED TRANSVERSELY THROUGH THE CASING AND THE DOOR AND HAVING KNOB-LIKE MEMBERS ON THE ENDS, ESCTUCHEON PLATES FOR FIXING ONTO THE DOOR FACES AND PRESENTING MEANS FOR SLIDABLE AND NONROTATABLE LOCATION OF THE BAR, STOP MEANS LIMITING THE SLIDING MOVEMENT OF THE BAR TO TWO ALTERNATIVE POSITIONS, SPRING MEANS ENGAGING AN ESCUTCHEON PLATE AND A PROJECTION ON THE BAR FOR BIASSING THE BAR AND ASSOCIATED PARTS TO ONE OF TWO ALTERNATIVE POSITIONS OF THE BAR, A PASSAGE ACROSS A PORTION OF THE BAR, A FORMATION ON THE MOUNTING ANY POSITION OF THE BAR, A FORMATION ON THE MOUNTING MEMBER SLIDABLY ENGAGEABLE ALONG THE PASSGE WHEN IN ALIGNMENT THEREWITH FOR LONGITUDINAL CATCH RETRACTING MOVEMENT OF THE LATCH BOLT, A PAIR OF CONVERGINGLY ARRANGED FACES ON OPPOSITE SIDES OF THE STRIKER PLATE ADAPTED FOR SWINGING THE LATCH BOLT IN TRANSVERSE DIRECTIONS WHEN THE CATCH IS THRUST ONTO THE STRIKER PLATE AND FOR EFFECTING CATCH RETRACTION BY A WEDGING ACTION ON OPENING AND CLOS-/ ING OF THE DOOR, AND SHOULDER MEANS ON THE MOUNTING MEMBER ENGAGEABLE ACROSS THE BAR WHEN THE MOUNTING MEMBER IS NOT IN ALIGNMENT WITH THE PASSAGE FOR BLOCKING THE LONGITUDINAL MOVEMENT OF THE LATCH BOLT, SAID ALIGNMENT BEING ATTAINED, ON OPENING OF THE DOOR, BY DISPLACING THE BAR TO AN ALTERNATIVE POSITION AGAINST THE ACTION OF ITS BIASSING SPRING MEANS WHILE THE LATCH BOLT IS SWUNG IN ONE DIRECTION BY TRANSVERSELY DIRECTED PRESSURE BETWEEN THE CATCH AND ONE OBLIQUE FACE OF THE STRIKER PLATE, WHEREAS ON CLOSING THE DOOR THE MOUNTING MEMBER IS ALIGNED WITH THE PASSAGE WHEN THE LATTER IS IN THE POSITION RESILIENTLY MAINTAINED BY THE BIASSING SPRING MEANS OF THE BAR, BY SWINGING OF THE LATCH BOLT IN THE OPPOSITE DIRECTION WHEN STRIKING THE OTHER SIDE OF THE STRIKER PLATE. 